Question

For sake of simplicity, let’s assume I want to write an extension method for the type int? and int:

public static class IntExtentions
{
    public static int AddOne(this int? number)
    {
        var dummy = 0;
        if (number != null)
            dummy = (int)number;

        return dummy.AddOne();
    }

    public static int AddOne(this int number)
    {
        return number + 1;
    }
}

Can this be done using only 1 method?

Answer 1

Unfortunately not. You can make the int? (or whichever nullable type you are using) method call the non nullable method very easily though, so you don’t need to duplicate any logic with 2 methods – e.g.

public static class IntExtensions
{
    public static int AddOne(this int? number)
    {
        return (number ?? 0).AddOne();
    }

    public static int AddOne(this int number)
    {
        return number + 1;
    }
}